Acanthamoeba castellanii

Phylogeny	Superclass Sarcodina
Preferred definitive host	It is, in fact, an opportunistic free-living soil amoeba Accidental parasite, causes ocular amebiasis among individuals who prepare their own saline with tap water for cleaning contact lenses.
Geographical location	Cosmopolitan
Organs affected	Cornea of eye
Symptoms & clinical signs	From: http://cms.revoptom.com/handbook/oct02_sec3_2.htm · present with a unilateral, red, painful eye. · Initially, there is typically a non-specific epitheliopathy which can progress to ulceration with infiltration. · Another common finding is radial keratoneuritis, or perineuritis; this involves irregularly thickened corneal nerves in the anterior to mid-stroma with shaggy borders. · About half of patients report significant pain, the rest experience only mild irritation and foreign-body sensation.^4,5 · Rarely is Acanthamoeba keratitis correctly diagnosed in the early stage. It typically follows a chronic course that waxes and wanes over weeks to months and never fully heals despite seemingly appropriate therapy. In fact, the diagnosis is often finally made when all other treatments fail.
Treatment	Management: · Treatment of Acanthamoeba keratitis is difficult due to the organism's ability to encyst with the use of topical medications. · Effective medications include topical polyhexamethylene biguanide (PHMB), propamidine isethionate (Brolene), chlorhexidine digluconate 0.02%, polymixin B, neomycin and clortrimazole 1%. · In one series of 10 patients, the combination of Brolene and PHMB successfully cured all cases of Acanthamoeba keratitis. · Cautious introduction of topical steroids along with anti-amoebic therapy helped resolve the inflammation and provided symptomatic relief.